N62 170A vs. 180A Alternator?

BigBody · #1 12-16-2018, 02:08 AM

Hi guys,

Anyone know the difference between 170 & 180 amp Valeo N62 alternator? Are they interchangeable? Realoem says, "Please determine the installed alternator independently or via diagnosis".

https://www.realoem.com/bmw/enUS/sho...44#12317540994

Thanks

crystalworks · #2 12-16-2018, 02:51 AM

I'm not sure. I currently have the 170A in the truck... but when it goes I have a 180A sitting on the shelf. I've upgraded alternators in the past on vehicles but those were a chassis or two older.

SlickGT1 · #3 12-16-2018, 12:05 PM

Lots of people go for the 180 when replacing. I never heard of any issues with people “upgrading”.

mr_robot · #4 12-16-2018, 03:02 PM

Might be with the options the car came equipped with from factory. If you have more electronics like 2 axle air suspension and etc it might come with 180 vs 170, just my assumption.

BigBody · #5 12-16-2018, 05:28 PM

Quote:

Originally Posted by mr_robot

Might be with the options the car came equipped with from factory. If you have more electronics like 2 axle air suspension and etc it might come with 180 vs 170, just my assumption.

Makes sense. I'll probably take the risk & go with the 180a. I don't have 2 axle air, but I do have a sub. Whats weird is that on realoem, it says the 180a only came on the 4.4 LCI. Maybe the 4.8 180a is a separate part number, i'm not sure. Also looks like the 180a is available new, but the 170's are mostly remanufactured...

BigBody · #6 12-16-2018, 05:35 PM

Just did some more investigating on realoem. E70 N62 also has 220 & 230 amp... wonder if they'd work...

crystalworks · #7 12-18-2018, 03:07 PM

^That's a good question. Sizeable bump in output vs the E53.

Edit: don't think it will work. I think the e70 alternator is without voltage regulator and relies on the IBS to determine charge voltage.

wpoll · #8 12-18-2018, 04:16 PM

Quote:

Originally Posted by crystalworks

^That's a good question. Sizeable bump in output vs the E53.

Edit: don't think it will work. I think the e70 alternator is without voltage regulator and relies on the IBS to determine charge voltage.

There would have to be a VR somewhere in the system - the alternator's raw output is likely to climb to many more volts than the various systems in the car can handle - like 15-20v.

I'm pretty sure the E70 alternator has the VR on the back, the same as the E53 - it's rated output voltage is 14v indicating there's a VR on board...

crystalworks · #9 12-18-2018, 07:05 PM

The e70 (dme maybe) uses the ibs to adjust charging voltage to compensate for battery age/degradation. This is why you have to register a new battery.

wpoll · #10 12-18-2018, 07:15 PM

Quote:

Originally Posted by crystalworks

The e70 (dme maybe) uses the ibs to adjust charging voltage to compensate for battery age/degradation. This is why you have to register a new battery.

Correct - the IBS does "regulate" the charge to the battery but this is a separate "regulator" from the main VR on the alternator. The two are in effect in series.

Also, it seems that not all alternators for the E70 range have a higher output rating than the E53 alternators - many variants are also rated at 170A/180A. I guess it's engine specific.

I haven't looked but are the mount points/electrical connectors/pulleys etc. the same? If the engine variant is the same family (i.e. 2005 E53 3.0d M57TU vs 2006 E70 3.0d M57TU2) then mount points/electrical connectors/pulleys might be the same but it seems like just another variable to take into account for not much gain.

Remember, you only need the power output your car can use - providing more power capacity doesn't mean the car can/will use it - unless you have added accessories that have a high power load.